Pb+ ions have been implanted into LiNbO3 crystals in the energy range of 100-350keV at doses of 5 x 10(15), 1 x 10(16) and 2 x 10(16) ions/cm(2). The profile of the implanted ions was measured by Rutherford backscattering. The mean projected range and the range straggling obtained from the experiment were compared with the TRIM'98 and SRIM 2000 code. In the present case, the TRIM'98 code predicts experimental values better than those of the SRIM 2000 code. The depth distribution is also found to be independent of dose for 350keV Pb+ implanted into LiNbO3 crystals. After 800 degreesC annealing for 60 min in ambient air, obvious diffusion occurs to the implanted Pb+ ions at 150 keV with a dose of 5 x 10(15) ions/cm(2). After a low-temperature treatment at 77K in liquid nitrogen, no obvious diffusion phenomenon occurs for the implanted Pb+ ions in LiNbO3.